On 31 March 2011, Mayotte officially became the 101st French
Department and the 5th French Overseas Department. Mayotte is also a Region, but with a single Executive and a single Assembly (General Council).
The official results of the referendum organized in 2009 to change the status of Mayotte from a Collectivity to a Department are:
Registered voters: 71,420
Actual voters: 43,331
Valid ballots: 43,215
Voter turnout: 61,37%
Yes: 41,160 (95,24%)
No: 2,055 (2,88%).

The new status is prescribed by two laws (Organic Law No. 1486 and Law
No. 1487) adopted on 23 November 2010 by the National Assembly,
promulgated on 7 December 2010 and published on 8 December 2010 in the
French official gazette (text).

Ivan Sache, 3 April 2011

History of Mayotte

The Sultanate of Mayotte was sold by Sultan Adriansouli on 25 April 1841 to Commandant Passot, who was looking for a port for the French Navy. In spite of the opposition of the United Kingdom and of the other local sultans, the purchase was ratified by King Louis-Philippe on 10 February 1843; Mayotte was formally annexed by France on 13 June 1843, a fact recognized by Anjouan in September 1843.
On 29 August 1843, Mayotte was incorporated into the Settlements of Nossi-Bé and Dependencies, administrated from Bourbon Island (today Reunion). Made a distinct settlement on 1 January 1846, Mayotte was incorporated from 1896 to 1968 into the Comoros.
By referendum, Mayotte decided twice (December 1974 and February 1976) to remain French and not to join the Republic of Comoros, which has maintained territorial claims on Mayotte since then (highlighted by the fourth star on the national flag).
By the Law #2001-616 of 11 July 2001, Mayotte became a collectivit&eacute départementale d'outre-mer.

Ivan Sache, Pascal Vagnat & Željko Heimer, 16 May 2009

Official flag of Mayotte

Local flag of Mayotte

Local flag of Mayotte - Image by Pascal Vagnat, 16 April 2004

The local flag of Mayotte, hoisted in front of the General Council,
along with the French national flags and other non-identified flags (photo, L'Express, 12 April 2004), is white with the coat of arms of Mayotte surmounted by "MAYOTTE" in red letters.

The arms of Mayotte, created by Michel Chabin, former Director of the
Archives of Reunion, and designed by the local artist Pascal Santerre, were adopted on 23 July 1982 by the General Council of Mayotte. Therefore, while the flag is unofficial, the coat of arms is,
actually, official.

The colors of the arms are those of the French flag.
The crescent recalls that 97% of the islanders are (Sunni) Muslims.
The ylang-ylang flower is produced by the cananga tree (Cananga
odorata [Lam.] Hook & Thomson), native from South-East Asia and grown on 9% of the arable land of Mayotte. The essential oil extracted from
the flower represents 25% of the exports of Mayotte (20 t per year)
and even 50% when reexports are excluded; Mayotte is nicknamed
"Perfume Island".
The engrailed border represents the coral barrier that surrounds the
lagoon of Mayotte, which is the largest enclosed lagoon in the world.
The sea horses allude to the shape of the biggest island (Grande Terre).

The motto Ra Hachiri means "We are vigilant".

Postage stamp with the arms of Mayotte - Scan by Ivan Sache, 10 February 2005

The coat of arms is shown on a postage stamp released by the French postal administration in 1997.

Ivan Sache, 23 May 2009

Alleged banner of arms of Mayotte

Flag proposal for Mayotte - Image by Pascal Vagnat, 2 April 2003

I designed a flag proposal for Mayotte long time ago, made of a banner of the arms of Mayotte. It appears that the design of this non-existent flag was released in the vexillological world, copied and further spread. However, I doubt very much that this flag ever existed in the real world.

FD, a left-wing political party based in Moroni, Republic of Comoros, have a branch in Mayotte and it is perfectly natural that they would be in favor of national unity. I have never heard of them having a flag, though, and I know the leader of the FD fairly well (he was my neighbour for two years). And yes, there are people on Mayotte who are pro-Comoros (admittedly not many...)

Iain Walker, 14 February 2000

The flag of FD is shown on the Flags of Aspirant
Peoples chart[eba94], No. 33, with
the following caption:
MAYOTTE (Comoro Islands Democratic Front)
East Africa;
based on written description.